LM137/LM337 3-Terminal Adjustable Negative Regulators

LM137/LM337
3-Terminal Adjustable Negative Regulators
General Description
The LM137/LM337 are adjustable 3-terminal negative voltage regulators capable of supplying in excess of b1.5A
over an output voltage range of b1.2V to b37V. These
regulators are exceptionally easy to apply, requiring only 2
external resistors to set the output voltage and 1 output
capacitor for frequency compensation. The circuit design
has been optimized for excellent regulation and low thermal
transients. Further, the LM137 series features internal current limiting, thermal shutdown and safe-area compensation, making them virtually blowout-proof against overloads.
The LM137/LM337 serve a wide variety of applications including local on-card regulation, programmable-output voltage regulation or precision current regulation. The LM137/
LM337 are ideal complements to the LM117/LM317 adjustable positive regulators.
77 dB ripple rejection
Excellent rejection of thermal transients
50 ppm/§ C temperature coefficient
Temperature-independent current limit
Internal thermal overload protection
P a Product Enhancement tested
Standard 3-lead transistor package
Output is short circuit protected
Y
Y
Y
Y
Y
Y
Y
Y
LM137 Series Packages and Power Capability
Device
Package
Rated
Power
Dissipation
Design
Load
Current
LM137/337
TO-3 (K)
TO-39 (H)
20W
2W
1.5A
0.5A
LM337
TO-220 (T)
15W
1.5A
Features
Y
Y
Y
Y
Y
Output voltage adjustable from b1.2V to b37V
1.5A output current guaranteed, b55§ C to a 150§ C
Line regulation typically 0.01%/V
Load regulation typically 0.3%
Excellent thermal regulation, 0.002%/W
Typical Applications
Adjustable Negative Voltage Regulator
TL/H/9067 – 1
Full output current not available at high input-output voltages
b VOUT e b 1.25V
#1
a
R2
120X
J #
a
b IADJ c R2
² C1 e 1 mF solid tantalum or 10 mF aluminum electrolytic required for stability
J
*C2 e 1 mF solid tantalum is required only if regulator is more than 4× from power-supply filter capacitor
Output capacitors in the range of 1 mF to 1000 mF of aluminum or tantalum electrolytic are commonly used to provide improved
output impedance and rejection of transients
C1995 National Semiconductor Corporation
TL/H/9067
RRD-B30M115/Printed in U. S. A.
LM137/LM337 3-Terminal Adjustable Negative Regulators
January 1995
Absolute Maximum Ratings
Operating Junction Temperature Range
b 55§ C to
LM137
LM337
0§ C to
b 65§ C to
Storage Temperature
Lead Temperature (Soldering, 10 sec.)
Plastic Package (Soldering, 4 sec.)
ESD Rating
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
(Note 4)
Power Dissipation
Internally Limited
Input-Output Voltage Differential
40V
a 150§ C
a 125§ C
a 150§ C
300§ C
260§ C
2k Volts
Electrical Characteristics (Note 1)
Parameter
LM137
Conditions
Min
LM337
Typ
Max
Min
Units
Typ
Max
Line Regulation
Tj e 25§ C, 3V s lVIN b VOUTl s 40V
(Note 2) IL e 10 mA
0.01
0.02
0.01
0.04
%/V
Load Regulation
Tj e 25§ C, 10 mA s IOUT s IMAX
0.3
0.5
0.3
1.0
%
Thermal Regulation
Tj e 25§ C, 10 ms Pulse
%/W
0.002
0.02
0.003
0.04
Adjustment Pin Current
65
100
65
100
mA
Adjustment Pin Current Charge 10 mA s IL s IMAX
3.0V s lVIN b VOUTl s 40V,
TA e 25§ C
2
5
2
5
mA
Reference Voltage
Tj e 25§ C (Note 3)
3V s lVIN b VOUTl s 40V, (Note 3)
10 mA s IOUT s IMAX, P s PMAX
Line Regulation
3V s lVIN b VOUTl s 40V, (Note 2)
0.02
0.05
0.02
0.07
%/V
Load Regulation
10 mA s IOUT s IMAX, (Note 2)
0.3
1
0.3
1.5
%
Temperature Stability
TMIN s Tj s TMAX
0.6
Minimum Load Current
lVIN b VOUTl s 40V
lVIN b VOUTl s 10V
lVIN b VOUTl s 15V
2.5
1.2
5
3
2.5
1.5
10
6
mA
mA
1.5
0.5
2.2
0.8
3.5
1.8
1.5
0.5
2.2
0.8
3.7
1.9
A
A
0.24
0.15
0.4
0.17
0.15
0.10
0.4
0.17
A
A
0.003
%
60
77
dB
dB
Current Limit
K and T Package
H Package
lVIN b VOUTl e 40V, Tj e 25§ C
K and T Package
H Package
b 1.225 b 1.250 b 1.275 b 1.213 b 1.250 b 1.287
b 1.200 b 1.250 b 1.300 b 1.200 b 1.250 b 1.300
RMS Output Noise, % of VOUT Tj e 25§ C, 10 Hz s f s 10 kHz
Ripple Rejection Ratio
0.6
0.003
VOUT e b10V, f e 120 Hz
CADJ e 10 mF
66
60
77
66
V
V
%
Long-Term Stability
Tj e 125§ C, 1000 Hours
0.3
1
0.3
1
%
Thermal Resistance,
Junction to Case
H Package
K Package
T Package
12
2.3
15
3
12
2.3
4
15
3
§ C/W
§ C/W
§ C/W
Thermal Resistance,
Junction to Ambient
(No Heat Sink)
H Package
K Package
T Package
140
35
140
35
50
§ C/W
§ C/W
§ C/W
Note 1: Unless otherwise specified, these specifications apply b 55§ C s Tj s a 150§ C for the LM137, 0§ C s Tj s a 125§ C for the LM337; VIN b VOUT e 5V; and
IOUT e 0.1A for the TO-39 package and IOUT e 0.5A for the TO-3 and TO-220 packages. Although power dissipation is internally limited, these specifications are
applicable for power dissipations of 2W for the TO-39 and 20W for the TO-3 and TO-220. IMAX is 1.5A for the TO-3 and TO-220 packages, and 0.2A for the TO-39
package.
Note 2: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are
covered under the specification for thermal regulation. Load regulation is measured on the output pin at a point (/8× below the base of the TO-3 and TO-39
packages.
Note 3: Selected devices with tightened tolerance reference voltage available.
Note 4: Refer to RETS137H drawing for LM137H or RETS137K drawing for LM137K military specifications.
2
Schematic Diagram
TL/H/9067 – 2
Thermal Regulation
In Figure 1 , a typical LM137’s output drifts only 3 mV (or
0.03% of VOUT e b10V) when a 10W pulse is applied for
10 ms. This performance is thus well inside the specification
limit of 0.02%/W c 10W e 0.2% max. When the 10W
pulse is ended, the thermal regulation again shows a 3 mV
step at the LM137 chip cools off. Note that the load regulation error of about 8 mV (0.08%) is additional to the thermal
regulation error. In Figure 2 , when the 10W pulse is applied
for 100 ms, the output drifts only slightly beyond the drift in
the first 10 ms, and the thermal error stays well within 0.1%
(10 mV).
When power is dissipated in an IC, a temperature gradient
occurs across the IC chip affecting the individual IC circuit
components. With an IC regulator, this gradient can be especially severe since power dissipation is large. Thermal
regulation is the effect of these temperature gradients on
output voltage (in percentage output change) per Watt of
power change in a specified time. Thermal regulation error
is independent of electrical regulation or temperature coefficient, and occurs within 5 ms to 50 ms after a change in
power dissipation. Thermal regulation depends on IC layout
as well as electrical design. The thermal regulation of a voltage regulator is defined as the percentage change of VOUT,
per Watt, within the first 10 ms after a step of power is
applied. The LM137’s specification is 0.02%/W, max.
LM137, VOUT e b 10V
VIN b VOUT e b 40V
0.25A
0A
IL e 0A
Horizontal sensitivity, 20 ms/div
x
TL/H/9067 – 3
LM137, VOUT e b 10V
VIN b VOUT e b 40V
0.25A
0A
IIL e 0A
Vertical sensitivity, 5 mV/div
x
x
FIGURE 2
x
FIGURE 1
3
TL/H/9067 – 4
Connection Diagrams
TO-39
Metal Can Package
TO-3
Metal Can Package
Case Is Input
Case is
Input
TL/H/9067 – 6
Bottom View
Order Number LM137H, LM137H/883 or LM337H
See NS Package Number H03A
TL/H/9067–5
Bottom View
Order Number LM137K/883
See NS Package Number K02C
Order Number LM337K STEEL
See NS Package Number K02A
TO-220
Plastic Package
TL/H/9067 – 7
Front View
Order Number LM337T
See NS Package Number T03B
4
Typical Applications (Continued)
Adjustable Lab Voltage Regulator
b 5.2V Regulator with Electronic Shutdown*
TL/H/9067 – 10
*Minimum output j b 1.3V when control input is low
Full output current not available
at high input-output voltages
*The 10 mF capacitors are optional to improve ripple rejection
TL/H/9067 – 9
Current Regulator
Adjustable Current Regulator
1.250V
R1
*0.8X s R1 s 120X
IOUT e
IOUT e
TL/H/9067 – 11
# R1 J
1.5V
g 15% adjustable
TL/H/9067 – 12
Negative Regulator with Protection Diodes
High Stability b10V Regulator
TL/H/9067 – 14
TL/H/9067 – 13
*When CL is larger than 20 mF, D1 protects the LM137 in case the input
supply is shorted
**When C2 is larger than 10 mF and b VOUT is larger than b 25V, D2 protects the LM137 in case the output is shorted
5
Typical Performance Characteristics (K Steel and T Packages)
Load Regulation
Current Limit
Adjustment Current
Dropout Voltage
Temperature Stability
Minimum Operating Current
Ripple Rejection
Ripple Rejection
Ripple Rejection
Output Impedance
Line Transient Response
Load Transient Response
TL/H/9067 – 15
6
7
Physical Dimensions inches (millimeters)
Metal Can Package (H)
Order Number LM137H, LM137H/883 or LM337H
NS Package Number H03A
Metal Can Package (K)
Order Number LM337K STEEL
NS Package Number K02A
8
Physical Dimensions inches (millimeters) (Continued)
Mil-Aero Metal Can Package (K)
Order Number LM137K/883
NS Package Number K02C
9
LM137/LM337 3-Terminal Adjustable Negative Regulators
Physical Dimensions inches (millimeters) (Continued)
TO-220 Plastic Package (T)
Order Number LM337T
NS Package Number T03B
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